Silo



Oct. 18, 1932. c. B. ROSS 1,882,942

SILO

Filed June 15, 1931 3 Sheets-Sheet 1 y 104 rm M KE Oct. 18, 1932. c, 3. oss 1,882,942

-SILO Filed June 15, 1931 3 Sheets-Sheet 3 Patented Oct. 18, 1932 UNITED STATES PATENT OFFICE CHARLES B. ROSS, OF M ARIETTA, OHIO, ASSIGNOR TO MARIETTA CONCRETE CORPORATION, OF MARIETTA, OHIO, A CORPORATION OF OHIO sILo Application filed June 15,

This invention relates to certain improvements in silos; and the nature and objects of the invention will be readily recognized and understood by those skilled in the arts in volved in the light of the following explanation and detailed description of the accompanying drawings illustrating what I at present consider to be the preferred embodiments or mechanical expressions of my invention from among various other forms, arrangements, combinations and constructions of which the invention is capable within the spirit and the scope thereof.

The invention is primarily directed to those types of silos or other storage building structures which are built up and constructed from concrete, or other artificial stone and such like material staves or blocks, to form a circular structure; and specifically such structures which are characterized by a vertical series of built-indoor frames providing fill-' in; and discharging openings therethrough, and a vertically spaced series of exterior, horizontally disposed strengthening and-re- Enforcing bands, hoops or rings around the circular structure.

A general object of the invention is to practically elim nate or materially reduce certain difiiculties and disadvantages encoun- 30 ered with such above characterized stave constructed, exteriorly bound and reinforced circular structures, in order to structurally and mechanically simplify such structures while reducing the cost thereof both in material and in time and labor of construction and installation, as well as increasing the strength and materially adding to the appearance of such structures.

A main difiiculty and disadvantage with -uch a stave constructed structure, arises from the building-up and formation of the circular wall thereof from concrete or the like material staves of fiat, uncurved form, each having opposite vertical concave and onvex edges which interfit with the edges so formed of the adjacent staves. These fiat concrete staves are placed in the wall edge to edge and in order to form a circular wall thereof, are necessarily set at an angle to each other, which results in a vertical groove be- 1931. Serial No. 544,596.

tween the adjacent, interfitted edges of the staves. The completed circular structure thus has a series of these vertical grooves" therearound, which not only materially detract from the finished appearance of the structure, but also present certain structural disadvantages. If these grooves are filled in with a suitablematerial, aside from the time and cost ofsuch operation, there is the difficulty of preventing cracking and chipping out of the filling, while on the other hand if the grooves are unfilled, water collects therein and freezes causing chipping or other damage to the staves and stage edges.

' A further object of my invention is to provide a design and construction of such staves or blocks for building circular structures, in which the opposite vertical, concave and con-- vex edges of each stave are so formed that when the staves are assembled in the required angular relation to each other'to provide the circular wall structure, the interfitted con-'- cave and convex vertical edges of adjacent staves, substantially fully meet and engage to eliminate an roove formin a s or vertical spaces therebetween on the outer or exterior side of the circular structure, and further to give to the interfitted adjacent staves the required angular relation to each other to define and form the desired wall curvature. 0..

With a silo or like circular storage structure it is generally necessary to increase the number of exterior strengthening or reinforcing bands or hoops around the lower portion thereof where the load of the contained 1 material is greatest and concentrated on the circular wall structure. 'Where the storage" building or silo is formed with a vertical series of door or like opening frames, certain of the exterior bands or hoops around the building will traverse or extend across the lower openings, so that it becomes necessary to provide for offsetting such bands vertically to pass around and between adjacent frames or openings. This necessity raises cer- 9 tain structural and mechanical difliculties which add to the expense of the structure and lower its efiiciency.

Another feature and object of my invention resides in the provision of an extremely me- 9 chanically simple yet highly efficient and relatively inexpensive design of exterior reinforcing and strengthening band or hoop spreader arrangement and construction for carrying the hoop or band over and around an opening providing door frame in the circular wall structure, without traversing, extending across and obstructing the wall opening, and in the design and formation of the door frame structure for cooperation with and operative engagement by the spreader to maintain and secure the spreader in position seated thereon against displacement, connecting and carrying a hoop or band around the opening and efliciently transmitting and distributing the loads and stresses thereto.

A further feaure and characteristic of the invention resides in the spreader engaging formation and structure of the door frames, by which the construction and mounting of an exterior, vertically disposed, material discharging chute on and over a vertical series of the door frames, is materially simplified and a high strength chute structure is made possible.

The invention is further characterized by a highly efiicient design of hinge and mounting for the doors or closures on the door frames, through the medium .of which the doors can be swung inwardly to open positions with the doors and hinges thereof completely removed from and unobstructing the door openings, while in closed position the door hinges and mountings are completely on the exterior of the structure removed from contact by the stored materi and provide in the case of a vertical series thereof, a ladder or such like structure by which one may climb up the exterior of the building structure.

With the foregoing general objects, features and results in view. as well. as certain others which will he readilv apparent from the following explanation, the invention con sists in certain novel features in construction and in combinations and relative arrangements of parts and elements, all as wvill be more fully and specifically referred to and set forth hereinafter.

Referring to the accompanying drawings, in which similar reference characters refer to corresponding parts throughout the several figures thereof:

Fig. 1 is a view in front elevation of a silo embody ing the several features of my invention, and constructed of th concrete staves or blocks of theinvention, the upper end or top of the silo not beingshown.

Fig. 2 is a transverse, horizontal section through the silo of Fig. 1, taken on the line 2-2 thereof, to show particularly the arrangement and mounting of the discharge chute over and on the exterior of the door frames. V i

Fig. 8 is a perspective view of one of the door frames of the invention, showing the outer face thereof with the spreader receiving and engaging surfaces or recess formed thereon.

Fig. i is a perspective view of one of the staves or blocks of which the silo of Fig. 1 is built-up and constructed. Fig. 5 is an end plan of the stave of Fig. 5, showing the formation of the opposite vertical concave and convex edges in accordance with the invention.

Fig. 6 is a view in elevation of a portion of the silo of Fig. 1, showing two adjacent door frames with the hoop spreader arrangements positioned and engaged thereon and thereover.

Fig. 7 is a'horizontal, transverse section through the portion of the silo and taken on the line 7-7, of Fig. 6, showing'particularly the formation of the circular silo wall through the interfitted adjacent staves of the invention, the open position of one of the doors and its hinge mounting being indicated in dotted lines.

Fig. 8 is an elevation of a portion of a silo and door frame to show a modified form of spreader mounting and engaging members on the door frame.

Fig. 9 is a detail horizontal section through a portion of the door frame and one of the modified spreader mounting members taken on the line 9 -9, of Fig. 8.

In the particular example of one possible form and arrangement of structure embodying the several features and characteristics of my invention, presented herewith for purposes of explanationand not by way of limitation, a silo S, or other circular wall structure or storage building, such as shown by Fig. 1 of the accompanying drawings, is constructed and built-up of the staves, sections, or blocks 10. These staves 10 in this particular instance are of relatively elongated, rec'- tangular and flat form, and are placed end to end in vertical tiers 10a (see Figs. 1 and 6) with the joints 10?) between the staves 10 of each tier breaking joints with the joints 10b of the adjacent tiers, the vertical edges of the staves of each tier being engaged by and interlitting with the adjacent vertical edges of the adjacent tiers at opposite sides thereof. In order to form the circular wall of the silo S, it is of course necessary with the flat form of staves 10, to place each vertical tier at the required angle to the adjacent tier to obtain a circular wall structure of the desired diameter, as will be clear by referring dinal convex rib or tongue 12 and the shoulders or faces 12a and 12b at opposite sides thereof; and the opposite vertical or longitudinal edge of the stave with the vertical or longitudinal groove let and the faces or shoulders 14a and 146 at opposite sides of the groove 14. One side or face 15 (the outer side when the stave is assembled in a curved or circular wall) of each stave 10 is formed of a greater width than the opposite or inner side or face 16 thereof (see Fig. 5), and the opposite vertical edges of the stave providing shoulders 12a-12b, and 1la1 lb, respectively, have their respective shoulders disposed in vertical planes along or on radii of the curve defined by the circular wall to be built-up from the staves'lO (see Figs. 2 and 7 With the staves 10 so formed and constructed, a curved or circular wall is built-up therewith, such as the circular wall of the silo S, by disposing the staves in the vertical tiers 1065 with their widest sides 15 on and forming the outer side of the wall, and the tongues 12 of the staves of each tier fitting into the grooves 14 of the staves of the tier adjacent thereto. WVith the shoulders 1261-126 of each stave 10 fully meeting and engaging with the shoulders 14al4b, respectively, of the adjacent stave into the groove 14 of which its tongue 12 fits, the stavcs are given the required angular relation to each other to form the curved or circular wall of the desired diameter, and no space or gap is formed between the meeting nd engaging outer side shoulders 12a and later of the interfitted staves. In this manner all groove forming spaces or gaps between the vertical edges of the interfitt-ed wall forming staves 10 are eliminated and the exterior or outer side face of a wall built therefrom presents a smooth, finished appearance, the joints 100 between staves 10 being substantially closed. (See Figs. 1, 2 and 6.)

lVhile the foregoing stave or block design and formation of my invention is of particular utility and efficiency with staves of the concrete or artificial material and the like types, its application is not so restricted, but can be carried out in wood or other material taves. Also, my invention is not limited in all respects to the formation of the staves with flat ends 11, as the invention contempla es and includes, where found expedient, the provision of ton 0'116 and groove, or concave and onvex stave ends, as will be readily apparent and understood.

In silos and similar types of storage buildings, it is desirable to provide openings at various heights through the silo wall for dis- "harge of stored materials from the silo. Usually such openings are arranged in a vertically alined series the silo wall, and are provided with suitable closures or doors by which the openings can be ClOS$C.

In the resent example, referring to Fi 1, I have shown the silo S as having a series of door frames F built-into the wall and normally closed by the doors D. The door framesF are placed in position in the wall one upon the other to form a vertical tier or series thereof extending from adjacent the lower end of the silo substantially throughout the height thereof, so as to provide the series of vertically spaced openings in proximity to each other through the wall of the silos.

In the specific embodiment hereof, each of the door frames F is formed of a concrete frame of relatively flat, rectangular form having the flat upper and lower opposite edges 20; one vertical edge provided with rib or tongue 21 and opposite shoulders 21a and 21b 5 and the opposite vertical edge formed with groove 22 and the opposite shoulders 22a and 22b. "The arrangement of tongue 21 and groove 22 with their opposite shoulders, is similar to that described in connection. with staves 10, and the door frames F are builtinto the wall of silo S with the tongues 21 fitting into grooves 14 of adjacent staves 10, and groove 22 receiving tongues 12 of the staves 10 adjacent thereto. The staves 1O interfitted with the opposite vertical edges of the door frames F are given the required angular relation with respect thereto by the formation of the door frames as wider on the outer side than'c-n the inner, and the angles of the shoulders 21a21b, and 22a22b, as on the radii of the curve of the silo wall, all as previously explained with respect to staves 10. The foregoing formation of the door frames F is clearly disclosed in Figs; 3 and 7 of the drawings in particular. The silo S is externally braced and reinforced against internal loads, by the exterior bands, hoops or rings 25 suitably adjustably clamped and secured around the wall at vertically spaced intervals throughout substantially the height of the silos, the bands 25 eX- tending around the silo wall between the openings provided by the door frames F (see Fig. 1). However, as the internal loads to which the silo wall is subjected by stored material therein, increase at the lower end of the silo, 7 it is usually necessary or advisable to increase the number of such exterior strengthening bands or hoops around the lower end portion of the silo, and in the instant example, additional hoops or bands 26 are applied around the wall spaced between the bands or hoops 25. This location of the bands 26 is such that they lie in a plane to traverse and extend over and across the openings in the door frames F. which would result in their obstructing and materially interfering with the use of such openings, and a further feature of my invention resides in an arrangement for spreading and efficiently carrying and disposing bands or hoops 26 over and around the openings in and provided by the door frames F.

For example, referring particularly to Fig.

6 in connection with Fig. 1 of the drawings, the ends of each band or hoop 26 are spaced apart so as to lie and be disposed at opposite sides of the door frame F adjacent thereto, and a spreader arrangement 30 is disposed over and across each door frame around the opening therein and is connected at opposite sides to and joining the adjacent ends of its respective hoop 26. In the specific form of such a spreader 30 here shown, the spreader is constructed of the complementary sections 31 of a suitable material, such as a heavy metal wire or rod material, each of which sections is bent into a substantially U-shape havng the horizontally disposed base 31a with the inwardly extending but. outwardly diverged opposite end arms 31?) terminating at their ends in the hoop or bandreceiving eye-s 310 (see Figs. 6 and 7).

Each spreader 30 is placed in position across a door frame F with the base 31a of one section 31 above the door frame opening and its end arms 31b extended downwardly to the opposite ends, respectively, of the hoop Z6; and the other section 31 with its base 31a below the door frame opening and its end arms 31 0 extended upwardly to the opposite ends, respectively, of the hoop 26. The eyes 310 of the spreader sections 31 at opposite sides of the door frame F receive the adjacent ends, respectively, of the hoop or band 26, which extend therethrough and are adjustably secured therein and thereto by the nuts 26a (see Fig. 6) threaded onto the ends of "he hoop or band. In this manner bands or hoops 26 are connected and extended over and across the door frames F, but around and unobstructing. the frame openings.

Following an important feature of my in- "ention, each door frame F is formed and constructed for cooperative engagement by a spreader 30 mounted and disposed thereover, so as to maintain the: spreader against displacement and insure efficient distribution f forces from the spreader to the door frame, as well as enabling proper installation and mounting of the spreader and its connection thereof to itshoop or band with a mini mum of time and labor. The door frames F f the present embodiment are formed of concrete or the like artificial stone material, and referring to Fig. 3 of the drawings in particular, each door frame F is provided on its outer side along and at opposite sides of he door opening therethrough, with the abutments or ribs 23 formed integral therewith and projecting outwardly from the face of the door frame.

Each door frame abutment or rib 23, exands vertically of the frame with its opposite ends spaced from the upper and lower edges 20 of the door frame, and intermediate such edges 20 and the upper and lower edges of the door opening, respectively. The opposite, upper and lower ends of each abutment or rib 23 terminate in the horizontally disposed shoulders or seats 2st, which lie in the same horizontal plane and are alined with the upper and lower shoulders 24, respectively, of the opposite abutment or rib 23. The outer side edge of each abutment 23 provides the vertically disposed, flat shoulder or face 25 (see Fig. 3) projected outwardly from the outer edge of the door frame adjacent thereto, shoulders 25 forming at opposite sides of the door frame substantially flush outward continuations of the vertical edge shoulders 21a and 22a, respectively, of the door frame. The outer edge shoulder 25 of each door frame abutment or rib 23 is connected at-its opposite ends with the upper and lower end shoulders or 24, respectively, by the inwardly inclined shoulders or seats 26, will be clear by reference to Fig. 3.

A spreader 30 is mounted on and across a. door frame F, referring here to Figs. 6 and 7, with the upper section base 31afiseated on and extended across and between upper end shoulders of abuiments 23, and its arms 31. seated on and extending downwardly over inclined shou ders 26, respectively, while the lower spreader section base 310, seats on and across cne lower end abutment shoulders 24, with its arms seated on and extended upwardly over the adjacent inclined shoulders respectively. Thus, the abutments or ribs 23 receive a-ndare engaged by the spreader sections 31 and hold and maintainthe sections in ,p ositionon the door frame against deformation, pulling together, or displacement unoer the loads imposed thereon, while the arrangement is such that the loads are evenly and efficiently distributed from the spreader to the door frame. The integral abutments or ribs materially rein.- force and strengthen the door framestructure, and if desired reinforcing pins 23a can be provided at the corners of the abutments or ribs 23 where shoulders 2e join in clined shoulders 26, respectively. The spreaders 30 are structurally simple, as is the mounting thereof, and the necessity for connections between the Spreaders and adjacent silo hoops or hands 25 for strengthening purposes and to hold the spreaders against displacement or deformation under loads, is

eliminated.

In order to provide for ready discharge of contained material from a silo through the door openings, it is customary to mount and secure a discharge chute structure in vertically disposed position on the exterior of the silo over and across the door or discharge openings therein, will be readily understood by those skilled in the art. By my present invention, I have provided in combination with and including the hereinbefore described door frame structures F, an etii cient construction and mounting of a disi and easily erected,

"WhlCll are similar to the concrete staves 10 previously described and explained. The chute C is arched over and across the vertical series of door frames F to any height de-v sired and usually terminates spaced above the lowermost door frames F. The oppog site inner staves 10 of the chute C, referring particularly to Fig. 2, are vertically disposed with their inner edges bearing on and against, over and along the opposite ribs or projections 23, respectively, of the door frames F, adjacent and with the outer sides of such inner staves substantiallyflush, although not necessarily so, with the outer ver-' tical shoulders 23 of the door frame projections. The chute C is thus anchored and held firmly at its inner, opposite vertical edges, on the silo wall, against the vertical ribs 23 of the door frames F, and in position extending vertically over the door frame openings. 'A

series of bands or hoops 25 are placed around the exterior of chute C and are connected at their inner ends vto adjacent silo wall hoops 25, respectively, at opposite sides of the chute by any suitable connecting members 25".

The foregoing chute construction, mounting and connection of chute G on and to the door frames F, in and forming portions ofv the silo wall, eliminates the-necessity of cutting out or not-ching the inner edges of the opposite inner staves 10, because such inner staves are secured and bear against projections or ribs 23 and are thus disposed with the stave inner edges in a. plane above and to 1 pass over and across hoops 25, and whereemployed spreaders 30, as will be clear by reference to Fig. 2 of the drawings. As may be desired, the spaces between the portions of the door frames F below the projections or ribs 23, and the inner staves 10 extending, thereacross, can be filled in and sealed by cement or the like. Thus, a strong and rigid chute of relatively yet of sufiicient strength and durability to care for the relatively small strains and stresses to which it is subjected in use.

In Fig. 8 of the drawings, I have the closed a modified arrangement of a door frame F for seating and engaging a. hoop spreader 30 in position thereon and thereacross, and which arrangement while adapt ed to stone or concrete door frames, is also applicable to a wood or other material frame.

The door frame F does not include the abutments 23 of frame F, but in place thereof, circumferentially grooved knobs or pins 27 are secured in the door frame and projecting from the outer side thereof, in such locations simple structure, quickly I rigidity of chute is obtained.

vention, and hence er 30,when the spreader is mounted thereon and thereover. WVhile four of such members 27 are here shown, obviously additional ones canbe added if desired, alon the bases 31a of the upper andlower sprea er sections 31.

,I haveselected in this instance, a door D and its mounting for each door frame F or F, referring now to Figs. 6 and 7.,of the drawings, which includes the horizontal upper and lower hinge members 40 pivotally mounted at one end on pins 41 on the door frame F, and extending across and pivotally mounted at their opposite ends to the opposite side of the door D by the pins 42. These hinge members 40 are arched outwardly across the door, so that when a door D is swung inwardly to open position, it takes the position shown by dotted lines in Fig. 7, with the hinge members completely removed from door opening obstructing position, the door frame pivoted end portions lying against the adjacent edge. of the door opening. hinge members are interbraced by the cross braces 43 extending and secured therebetween, and suitable door locking latches or catchese are provided for securing a door D in closed position. With a-vertical series of doors. D so mounted, the hinge members 40 with their cross bracing 43 provide, in effect, a ladderstructure for climbing up the exterior of the silo. V

The several features and characteristics of my invention as described above obtain a. silo or similar curved wallstructure, fied construction with increased strength, and asilo or the like wall of materially improved external appearance, as well as greater wall durability, due tothe elimination of gaps or grooves between the staves or blocks of which it is built-up. The door frame construction and spreader arrangement cooperating therewith, obtain a mechanically simple yet highly eflicient solution of the problem of carrying hoops or bands over and across the door or opening frames without obstructing the openings, while the door frame construction also makes possible a. construction and mounting of a chute structure on the silo by which the desired strength and It is also evident that various changes, modifications, variations, substitutions and additions might be resorted to without departing from the spirit and scope of my in- I do not wish to limit myself in all respects to the exact and specific disclosures hereof. V

l/Vhat I claim, is:

1. In a silo having a circular wall, a series of vertically alined door frames built-into the wall, a series of exterior hoops around the wall disposed between the openings in The of simplisaid door frames, a series of hoops around the wall spaced between said first mentioned hoops, and spreaders extended across the door frames above and below the openings therein and connected at their opposite ends opening, a spreader extending across the door frame around and above and below the opening therein, the oppositeends of said hoop connected to said spreader at opposite sides of the door frame, and said door frame formed with shoulders thereon receiving and on which said spreader seats and is held in position against displacement.

3. In a silo, a door frame built-into the silo wall to provide an opening therethrough, a hoop around the exterior of the silo wall in a plane to extend across the door frame opening, the ends of said hoop spaced apart and disposed at opposite sides of but adjacent the door frame, the door frame formed with spaced horizontally disposed shoulders thereon above and below the opening therethrough, and a spreader extending across said door frame above and below the OPSIllIl and seated on and against saidupper and lower shoulders, respectively, the ends of said hoop connected to opposite sides of said spreader, respectively.

4. In a silo, a concrete or the like material door frame in the silo wall having an opening therethrough, a hoop around the exterior of the silo having its ends spaced apart and disposed at opposite sides of the door frame,

said door frame formed with a vertically disposed abutment integral therewith on the exterior thereof and projecting outwardly therefrom at each side of the door opening, the upper ends of said abutments providing spaced horizontal shoulders above the door opening and the lower ends of said abutments providing similar spaced horizontal shoulders below the door opening, a spreader formed of an upper section extended across the door frame. seated on the upper end shoulders of said abutments and a lower section extended across the door frame seated on the lower end shoulders of said abutments, the

end lengths of each of said sections at opposite sides of the door frame bent inwardly toward each other and connected by and to the adjacent end of said hoop, and the outer side edges of each of said abutments formed to provide seats for and conforming to the inwardly extended end lengths, respectively,

a door frame built-into theof the upper and lower sections of said spreader.

-5."ln a silo, a door frame in the silo wall, projecting ribs formed on the exterior of said door frame along opposite vertical edges thereof, and a vertically disposed chute on the exterior of the silo wall extending over said door frame, the spaced inner edges of said chute seated against and engaging said ribs, respectively, at opposite sides of the door frame.

6. In a silo, a door frame in the silo wall, a rib formed on the door frame projecting outwardly therefrom along each edge vertical side thereof to provide opposite side vertically disposed outwardly facing shoulders, a discharge chute built-up and arched outwardly over and across the door frame, the spaced inner ends of said chute engaged against said ribs, respectively, at opposite sides of the door frame, a hoop around the silo adjacent the door frame, and a hoop around the exterior of said chute connected at its opposite inner ends to said silo hoop at opposite sides, respectively, of the chute.

7. In a building, a curved wall structure having a dooropening therethrough, a reinforcing member on the'exterior of the wall structure in a plane to extend across the door opening, the ends of said reinforcing member spaced apart and disposed at opposite sides of the wall door opening, a spreader structure on the exterior of the wall extending above and below the wall opening, the ends of the reinforcing member connected to said spreader at opposite sides of the door opening, and means on said wall structure adjacent the door opening providing seats on which said spreader engages and is held on the wall structure against displacement.

- 8. In a silo and the like building structure, a-door frame built into the silo wall to provide an opening therethrough, a hoop on the exterior of the silo wall with its ends spaced apart and disposed at opposite sides of but adjacent the door frame, spaced, horizontally disposed and outwardly extending pin members fixed in said door frame above and below the door frame opening, and a spreader extending across said door frame above and below the opening and seated on and against said upper and lower pin members, respectively, the ends of said hoop connected to opposite ends of said spreader, respectively.

9. In a silo and the like building structure,

a door frame in the silo wall forming an opening therethrough, a hoop member aroundthe exterior of the silo wall having its ends spaced apart and disposed at opposite sides, respectively, of the door frame, at least a pair of spaced horizontally disposed, outwardly extended exteriorly headed and circumferen tially grooved pin members fixed in the door frame above and adjacent opposite sides of the frame opening, a similar pair'of pin members fixed in the door frame below and adj a cent opposite sides of the frame opening, and a spreader extending across said door frame above and below the frame opening, said spreader including an upper section mounted over and across and seated in the grooves of said upper pin members and a lower section mounted over and across and seated in the grooves of said lower pin members, the ends of said hoop member connected to the adj acent ends of said spreader, respectively, at opposite sides of the door frame opening.

10. In asilo and the like building structure, a door frame in the silo wall providing an opening therethrough, a hoop member around the exterior of the silo wall having its ends spaced apart and disposed at opposite sides, respectively, of the door frame, a spreader formed of an upper section of rod material extending across the door frame above the opening and a lower section of rod material extending across the door frame below the opening, the opposite ends of said upper and lower spreader sections extended inwardly to form horizontally alined eyes, and the ends of said hoop member extended through and removably secured in the adjacent alined eye forming ends, respectively, of the spreader sections, with the spreader connecting and securing the hoop in position without obstructing the door opening.

11. In a silo, a plurality of vertically alined door frames in the silo wall, a plurality of vertically spaced hoops secured around the exterior of the silo wall, a. vertically disposed chute structure built-up and arched outwardly over and across said door frames, the

spaced inner edges of said chute structure seated and held against inward displacement on the door frames at opposite sides of the frame openings, and hoops around the exterior of said chute and connected at their op posite inner ends to the silo hoops respectively adjacent thereto.

12. In a silo, a door frame in the silo wall providing an opening therethrough, a hoop around the exterior of the silo disposed in a plane which extends across the door frame opening, a spreader formed of a separate upper section extending across the door frame above the opening and a separate lower sec tion extending across the door frame below the opening therein, the opposite ends of said upper and lower spreader sections extended inwardly to and joined together in spreader forming assembly by the adjacent ends, respectively, of said hoop at opposite sides of the door frame opening, the spreader assembly connecting and joining the hoop ends, and

means maintaining said spreader sections against deformation and displacement on and with respect to the door frame.

Signed at Marietta, county of l/Vashington, State of Ohio, this 11 day of June, 1931.

CHARLES B. ROSS. 

